Crossing frogs for rails of railroad track and the like



CROSSING FROGS FOR RAILS OF RAILROAD TRACK AND THE LIKE Filed June 10. 1968 July 21, .1910 E. VON HAYN 5m 3 Sheets-Sheet 1 CROSSING FROGS FOR RAILS OF RAILROAD TRACK AND THE LIKE Filed June 10. 1968 E. VON HAYN ET AL July 21, 1970 3 Sheets-Sheet 2 July 21, 1970 E. VYON HAYN ET'IAL 3,521,053

CROSSING FROGS FOR RAILS OF RAILROAD TRACK AND THE LIKE Filed June 10. 1968 S Sheets-Sheet 5 United States Patent 3,521,053 CROSSING FROGS FOR RAILS OF RAILROAD TRACK AND THE LIKE Ernst von Hayn, Butzbach, Upper Hess, and Wilhelm Munch, Minden, Westphalia, Germany, assignors to Pintsch Bamag Aktiengesellschaft, Butzbach, Upper Hess, Germany Filed June 10, 1968, Ser. No. 735,909 Int. Cl. E011) 7/10 U.S. Cl. 246468 9 Claims ABSTRACT OF THE DISCLOSURE A crossing frog having two point rails with a movable portion adapted to be placed by a linkage, selectively against one or the other fixed wing rails. The ends of the point rails which merge together at the movable portion are fixedly welded to one another so that the movable portion of the frog forms a unitized assembly in which relative internal sliding movement is prevented.

BRIEF SUMMARY OF THE INVENTION This invention relates to crossing frogs having a movable point.

-It is known that a comparatively shock-free passage over switches can be obtained by the frog point or a wing railbeing so adjusted simultaneously with the shifting of' the switch blades, that both come into abutment with one another in the track being travelled over and no gap is left remaining between them. Earlier proposals in this direction have not heretofore been introduced into practical use. One recent solution provides a crossing frog with fixed wing rails and a movable point, which is always applied to the wing rail of the track being travelled over, corresponding to the position of the blade of the switch. In this case, the mobility of the point is facilitated by the arrangement in which, of the two point rails which form the point block or middle block of the crossing frog, either one is arranged to be laterally displaceable and the other is connected to the compact point by an oblique sliding position, or both point rails are arranged to be laterally displaceable and those ends of the point rails which merge together in the points are given a sliding connection by bolts, so that with the adjustment or switching'of the point by a linkage which acts thereon, in the first case one point rail and in the second case both point rails are resiliently bent laterally and the rail sections execute a short relative movement in the corresponding sliding position or connection. This possibility of a sliding movement when switching the point is considered to be necessary with the known switches, in order to make possible the elastic deflection of the point rails with small forces. However, this sliding position has considerable disadvantages. In the first place, it constitutes an additional junction in the running surface. Furthermore, the constant friction in operation, promoted by the impacts of the wheels rolling on the track, leads in a short time to such a degree of wear and formation of ashoulder or burring that the advantages of the adjustability of the point are lost, and the frog requires frequent repairs.

The invention avoids the disadvantages of the known arrangements, and is directed to a switch frog with a movable point, which is adapted to be applied alternately by a linkage acting thereon against the fixed wing rails, in which the point rails forming the middle block of the frog are arranged to be laterally displaceable on their support and are able to bend resiliently on switching the point. Such a crossing frog is characterized primarily, according to the invention, by the fact that those ends of the point rails, i.e. the main point rail and the secondary point rail, which merge in the point are welded to one another to form a rigid connection. As a result, any relative sliding movement within the frog middle block forming a complete unit is avoided. Rather, said block only experiences elastic deformation, and a switch frog with a movable point is formed, of which the premature wear by the operation of setting the switch is excluded.

Tests and calculations have surprisingly shown that, with a normal spreading angle of the point rails to be bent laterally, the forces which are necessary for shifting the point of the coherent block consisting of the two point rails are not excessively large and can be applied with a normal switch operating mechanism. The arrangement is advantageously such that the frog point, in the un deflected state, occupies a middle position between the two wing rails, so that the forces for switching the point, in both directions, are the same and have a minimum value.

In order to still further reduce the elastic forces, the region of the point rails capable of lateral bending can be provided with recesses in the rail base, where possible, as in the manner with resilient switch tongues.

The shifting of the frog point from one operative position to the other has to take place simultaneously with the shifting of the switch tongues. It is preferable to use the same drive means for both setting operations and that these be mechanically or electrically coupled. In the present invention, it is thus readily possible for a normal switch operating gear to be used for the shifting of the frog point.

Furthermore, the locking of the frog point in the operating position at any time can advantageously be effected with a locking means of the clamping point lock type, which is commonly used for switch tongues. This known locking means consists of two locking elements or boxes which are fixed beneath the cheek rails and which embrace the slide rod, and in which a clamp with a hammershaped or dovetailed head slides in and out as well as the slide rod. These clamps, which are pivotally arranged with the base ends on the tongue points, engage with their head in one end position on the closer tongue, behind the locking element, and in the other end position on the more distant tongue, and in a recess in the slide rod, which corresponds as regards shape and size to the head of the clamp. When using the switch operating gear, it is necessary to distinguish between three sections for the setting travel of the slide rod:

In the first section (preliminary travel), one of the clamps, of which the head engages in the recess of the slide rod, is also moved (together with its tongue), until the head of the other clamp can engage in the associated recess of the slide rod (and thus unlatch its tongue).

In the second section (main travel), both clamps (and both tongues) are accordingly driven until the head of one of the clamps emerges from the recess in the slide rod (and in this end position latches the tongue).

In the third section (final travel), it is only the other clamp (and its tongue) which is moved into the end position.

In order to employ this principle with the crossing frog according to the invention, the latter provides for the two clamps to be articulated on both sides on the rail base of the frog point and for the two recesses in the slide rod, in which the clamp heads engage alternately when switching the point, to be made longer than the clamp head, such that the slide rod, without driving one of the clamps, is able to cover that first section of the setting travel which is necessary for unlatching the other clamp. If the recess were not sufiiciently long for it to permit this idle travel of the slide rod, but if the latter were to be non-positively coupled prematurely with one of the clamps, the slide rod would be immovable, because one of the clamps is connected via the frog point fast with the other clamp. This circumstance, which is that the two clamps form a unit as regards the longitudinal displacement when used on the crossing frog, is further utilized according to the invention for the frog point to experience a double latching by the fact that one of the clamps is secured on the locking box and the other clamp engages in the slide rod, which is held by the retaining force of the operating mechanism in its position. Therefore, should one of the clamps break, the frog point remains secured by the other clamp.

BRIEF DESCRIPTION OF THE DRAWING An embodiment of the invention is illustrated by way of example in the appended drawing, wherein:

FIG. 1 is a plan view of the crossing frog, the point block of which is shown in the middle position for the sake of clarity,

FIG. 2 shows a detail of FIG. 1, with the frog point and the lock in one end position,

FIG. 3 is a section on the line IIIIII of FIG. 2,

FIG. 4 is a section on the line IV-IV of FIG. 1,

FIG. 5 is a section on the line V-V of FIG. 1, and

FIGS. 6a and 6b are diagrammatic views of the switch points in the two end positions.

DETAILED DESCRIPTION As seen in FIG. 1, the crossing frog of the switch according to the invention comprises essentially two fixed wing rails 1 and 2 and a frog point or middle block 3. The latter consists of the two point rails, namely, the main point rail 4 and the secondary point rail 5, which merge together in the point 3a proper and are here fixedly welded toone another along the seam 6. The main point rail 4 runs to a point at its free end, in such a way that it is able, in the operative positions, to bear without any gap against one or other of the wing rails, as is shown in FIG. 2.

The two wing rails 1 and 2 are advantageously united by welded spacer elements 7a, 7b, 76 into a rigid block, the spacer elements also serving as a sliding support for the point 3a. The wing rails are fixed, in conventional manner by clamping plates 8 and screws 9, to ribbed plates 10, which are screwed to the sleepers by means of screws 11. At the inner ends, the wing rails are fixed on the frame-like base plate of the block, to which they are additionally connected by dowels, as can be clearly seen from FIG. 3.

The point rails 4 and 5 of the middle block 3 widen towards the other end and are arranged over the major part of their length to be laterally displaceable on ribbed plates 10a (FIG. 4). Clamping plates 8a are fixed by screws 9a on the ribbed plates and serve as abutments or stops for the laterally displaceable point rails.

In FIG. 4, the point rails are shown in the middle position. Spacer elements 12 are fitted between the point rails and each is fixed only to one of the rails by means of a screw, the elements 12 preferably being connected alternately to the main point rail 4 and to the secondary point rail 5. These spacer elements, which advantageously bear on the inside surfaces of the upper and lower flanges of the point rails, serve the purpose of transmitting lateral wheel pressure, which is always exerted on that point rail which is not abutting the clamping plate, to the other point rail which is supported on its clamping plate.

The displaceable arrangement of the point rails, as previously described, serves to permit their resilient lateral outward bending. In order to facilitate this resilient movement, section-weakening recesses can be formed in a manner known per se in the corresponding region of the middle block or a part thereof in the rail bases, said recesses advantageously lying centrally between the ribbed plates and sleepers.

Beyond the region which can be bent laterally, the point rails 4 and 5 are fixed rigidly on their ribbed plates. In the arrangement shown in FIG. 1, this region is formed by the three last plates or pairs of plates at the right end of the central block. Of these plates, the first plate 10b (FIG. 5), adjoining the resilient region shown in section in FIG. 4, is provided with two dowels 214, which engage in holes in the bases of the two point rails and thus secure the position of the rails on the ribbed plate, in addition to the fixing by the clamping plates and screws.

It is shown in FIGS. 6a and 6b that each of the two point rails, on switching the point from one operative position into the other, alters its radius of curvature, and as regards the example of a simple right-handed switch, the numerical values which are set out below are only to be understood as exemplary:

The radius of curvature of the point rail 4a has a nominal value of infinity when the switch is set for a straight track, while it has a smaller value, e.g. 720 m., when the switch is set for a curved track;

The radius of curvature of the point rail 5a has its nominal value, e.g. 760 m., when the switch is set for a curved track, while it has a smaller value, e.g. 370 m., when the switch is set for a straight track.

These conditions are taken into account when preparing the point rails and uniting them with the point block, and it is in addition important in which position the point block is to be situated in the untensioned state. If the point is to occupy the middle position between the wing rails, as long as no setting forces are acting on them, the two point rails are to be so initially bent and united that their radii of curvature have corresponding values between the actual limiting values for the examples mentioned above.

A geared electrical motor 15, of a type used for operating switches, is provided in FIG. 1 as the operating mechanism for shifting the point 3a. A normal switch operating mechanism is advantageously used, provided that the setting forces applied by said mechanism are sufiicient to operate the crossing frog.

Coupled to the operating gear is a slide rod a of a point lock, which is used with the basic clamp-type point lock customary for switch tongues, as described above. The slide rod a is displaceable in two box-like lock elements b1 and b2 which are fixed on the base plate #3 and into which also projects from the inside clamps c and d which are pivoted on the rail base of the point 3a, said clamps each having respective dovetailed heads 01 and d1. The slide rod a has two recesses a1 and a2, the length of which is somewhat larger than the length of a clamp head, as indicated above, it also being necessary to take into account the stroke or adjusting path of the operating gear.

The lock boxes are of such width dimensions that, on switching the point 3a, each clamp is only movable therein if the clamp head is engaged in the recess of the slide rod, and on the other hand they are made snfficiently long for the corresponding clamp head to hook behind the limits of the locking box in the end position of the pomt. 1

The moving of the point 3a from the end position in FIG. 2 into the other end position thus takes place by the rod a being moved upwardly until the head d1 extends into the recess a2 (preliminary travel), then the head c1 bears and is moved together with the point, until the head 01 emerges from the recess and swings the clamp 0 into the latching position (main travel), whereupon this latching position is fixed by the subsequent setting movement of the rod (final travel) in exactly the same way as the latching position of the head d1 of the clamp d is fixed by the rod a in FIG. 2.

What is claimed is:

1. A crossing frog for two spaced main rails comprising two points rails inclined towards one another and having forward ends extending between said main rails, means fixedly securing each point rail at the rear thereof at a location spaced from said main rails, weld means fixedly securing the forward ends of the point rails together in the region between said main rails, said point rails each including resilient deformable intermediate portions between the forward and rear ends thereof, means engaging the thus fixedly secured point rails to laterally and resiliently bend the point rails as a unit between respective end positions against the main rails, and means supporting the point rails between the forward and rear ends thereof for laterally displaceable movement.

2. A frog as claimed in claim 1 wherein one of said point rails is a main point rail and the other of said point rails is a secondary point rail, the main point rail having a point shaped end which is applied against the main rails as the point rails are laterally bent.

3. A crossing frog as claimed in claim 1 wherein said intermediate portions of said point rails which can be bent laterally have rail bases which are provided with section- Weakening recesses.

4. A crossing frog as claimed in claim 1 wherein said means supporting the point rails between the forward and rear ends thereof comprises spacer elements between the point rails in the regions where they can be bent laterally, said spacer elements each being fixed to one of said point rails, successive spacer elements being fixed in alternation to said point rails.

5. A crossing frog as claimed in claim 1 wherein said means supporting the point rails between the forward and rear ends thereof comprises spacer members connecting the point rails to one another, said point rails being slidably supported on said spacer members in the region where said point rails are laterally bendable.

6. A crossing frog as claimed in claim 1 wherein said means for laterally bending the point rails comprises a slide rod and lock engagement means including two pivotable clamps on said point rails for respectively engaging said slide rod.

7. A frog as claimed in claim 6 comprising means for displacing the slide rod between first and second limit positions corresponding respectively to the engaged positions of the point rails with the main rails.

8. A frog as claimed in claim 7 wherein said slide rod has two recesses therein, said pivotable clamps each including a head for engaging a respective recess.

9. A frog as claimed in claim 8 wherein said recesses are elongated relative to the size of the heads on the clamps, such that one clamp is disengaged from the associated recess and rigidly latches the point rails and the other clamp additionally causes a securing of the point rails by engagement of the head thereof in the associated recess.

References Cited UNITED STATES PATENTS 470,486 3/ 1892 Hancox 246275 657, 66 8 9/ 1900 McKinney 246275 675,914 6/1901 Williams 246275 ARTHUR L. LA POINT, Primary Examiner R. A. BBRTSCH, Assistant Examiner 

